^{page 335 note 1} Read before the Agricultural Subsection of the British Association for the Advancement of Science, Winnipeg, 08. 27th, 1909.Google Scholar

^{page 336 note 1} Handbook of Canada, 1897.Google Scholar

^{page 337 note 1} Director of the Canadian Meteorological Service.Google Scholar

^{page 337 note 2} Handbook of Canada, 1897.Google Scholar

^{page 340 note 1} And here, perhaps, the opportunity best presents itself to say a word in reply to the question frequently asked as to the probable necessity of using superphosphate or other mineral fertilizers in the north-west. At present, at all events, there is no such necessity; over the larger portion of the prairie country, seasonal conditions undoubtedly to-day control the yields. As for the future, our work and observations lead us to believe that if the humus content of the soil is well maintained the day is far distant when there will be any need for phosphatic and potassio fertilizers.

^{page 340 note 2} In speaking of the invariably alkaline reaction of prairie soils, it may be remarked that their black colour—which undoubtedly is an important factor in their absorption of heat as soon as the season opens—results in all probability from the action of the alkaline compounds referred to on the organic matter and is not due to the presence of finely divided carbon from prairie fires as advanced by the late Dr. Geo M. Dawson.

^{page 345 note 1} As the soil had already gone through a 1 mm. sieve the fine gravel could not be determined.

^{page 350 note 1} There is at times a certain loss of surface loam in the older cultivated areas by drifting, and this in some cases would affect the phosphoric acid and potash content, and more especially that portion which is available.

^{page 350 note 2} A composite sample not dealt with in the table of chemical analysis.

^{page 350 note 3} As the soil had already gone through a 1 mm. sieve the fine gravel could not be determined.

^{page 352 note 1} In all instances, unless otherwise specified, the soil collections were made to a depth of 9 inches.

^{page 354 note 1} As the soil had already gone through a 1 mm. sieve the fine gravel could not be determined.

^{page 355 note 1} The data of this investigation will be found in the Report of the Chemist, Dominion Experimental Farms, 1900.Google Scholar

^{page 356 note 1} Unfortunately, fallowing is not without its concomitant evils. We have already pointed out that dissipation of humus and nitrogen results from continuous grain growing and that the greater part of this loss is more particularly consequent upon the stirring and opening up of the soil by repeated cultivation during the fallow season. It must now be stated that a further loss may result from fallowing; viz. the removal of more or less of the rich surface soil by erosion and drifting. The constant cultivation of the land breaks up the fibre—the binding element which gives the toughness to the prairie sod. As the fibre becomes shorter the surface loam more readily dries and pulverizes; it is then easily carried away by the strong winds which prevail at certain seasons in prairie regions. Very serious losses have occurred from this cause in some of the older cultivated districts of the north-west. The adoption of a cropping system in which the soil is occasionally put in sod suggests itself as the natural and best corrective